From 1 - 5 / 5
  • This Record presents data collected in July–August 2020 as part of the ongoing Northern Territory Geological Survey–Geoscience Australia SHRIMP geochronology project under the National Collaboration Framework agreement and Geoscience Australia's Exploring for the Future Program. New U–Pb SHRIMP zircon geochronological results derived from eight sedimentary samples from the western Amadeus Basin in the Northern Territory are presented herein. Detrital zircon U–Pb ages were determined from four samples of the Winnall Group: three samples of the Liddle Formation and one of the Puna Kura Kura Formation. Zircon U–Pb ages were also determined from two samples of the Pertaoorrta Group (Cleland Sandstone and Tempe Formation), one sample of the Larapinta Group (Stairway Sandstone) and one sample of the Mereenie Sandstone. <b>Bibliographic Reference:</b> Kositcin N, Verdel C, Normington VJ and Simmons JM, 2021. Summary of results. Joint NTGS–GA geochronology project: western Amadeus Basin, July–August 2020. <i>Northern Territory Geological Survey, Record</i> <b>2021-002</b>.

  • The preserved successions from the Mesoproterozoic Era (1600 to 1000 Ma) are a relatively understudied part of Australian geological evolution, especially considering that this era has a greater time span than the entire Phanerozoic. These rocks are mostly known in variably-preserved sedimentary basins overlying Paleoproterozoic or Archean cratons or at the margins of these cratons. Some metamorphosed equivalents occur within the orogens between or marginal to these cratons. Both energy and mineral resources are hosted in Australian Mesoproterozoic basins, including the highly-prospective organic rich shale units within the Beetaloo Sub-basin (Northern Territory), which form part of the Beetaloo Petroleum Supersystem. The primary aim for this record is to provide a consolidated state of knowledge of Australian basins or successions similar in age to that of the Mesoproterozoic Beetaloo Petroleum Supersystem. The findings of this report will assist prioritising future work, through improved geological understanding and resource prospectivity. This report presents an overview of 14 Mesoproterozoic-age sedimentary basins or successions and their current level of understanding, including location, basin architecture, stratigraphy and depositional environments, age constraints and mineral and energy resources. Basins or successions included in this record are unmetamorphosed or metamorphosed to very low-grade conditions. Recommendations are made for future work to address the main knowledge gaps identified from this review. While some of these basins have been the focus of recent intense study and data acquisition, the extent of knowledge varies broadly across basins. All basins reviewed in this record would benefit from further geochemical and geochronological analyses, and stratigraphic study to better understand the timing of depositional events and their correlation with nearby basins. Elucidation of the post-depositional history of alteration, migration of fluids and/or hydrocarbons would facilitate future exploration and resource evaluation.

  • <div>The interpretation of AusAEM airborne electromagnetic (AEM) survey conductivity sections in the Canning Basin region delineates the geo-electrical features that correspond to major chronostratigraphic boundaries, and captures detailed stratigraphic information associated with these boundaries. This interpretation forms part of an assessment of the underground hydrogen storage potential of salt features in the Canning Basin region based on integration and interpretation of AEM and other geological and geophysical datasets. A main aim of this work was to interpret the AEM to develop a regional understanding of the near-surface stratigraphy and structural geology. This regional geological framework was complimented by the identification and assessment of possible near-surface salt-related structures, as underground salt bodies have been identified as potential underground hydrogen storage sites. This study interpreted over 20,000 line kilometres of 20&nbsp;km nominally line-spaced AusAEM conductivity sections, covering an area approximately 450,000 km2 to a depth of approximately 500&nbsp;m in northwest Western Australia. These conductivity sections were integrated and interpreted with other geological and geophysical datasets, such as boreholes, potential fields, surface and basement geology maps, and seismic interpretations. This interpretation produced approximately 110,000 depth estimate points or 4,000 3D line segments, each attributed with high-quality geometric, stratigraphic, and ancillary data. The depth estimate points are formatted for Geoscience Australia’s Estimates of Geological and Geophysical Surfaces database, the national repository for formatted depth estimate points. Despite these interpretations being collected to support exploration of salt features for hydrogen storage, they are also intended for use in a wide range of other disciplines, such as mineral, energy and groundwater resource exploration, environmental management, subsurface mapping, tectonic evolution studies, and cover thickness, prospectivity, and economic modelling. Therefore, these interpretations will benefit government, industry and academia interested in the geology of the Canning Basin region.</div>

  • The Beetaloo Sub-basin, northern Australia, is considered the main depocentre of the 1000 km-scale Mesoproterozoic Wilton package of the greater McArthur Basin. The ca. 1.40-1.31 Ga upper Roper Group and the latest Mesoproterozoic to early Neoproterozoic unnamed group of the Beetaloo Sub-basin, together, record ca. 500-million-years of depositional history within the North Australia Craton. Whole-rock shale Sm-Nd and Pb isotope data reveal a dynamic interaction between sedimentary provenance and ancient tectonic geography. The ca. 1.35-1.31 Ga Kyalla Formation of the upper Roper Group is composed of isotopically evolved sedimentary detritus, whereas the upper portions of this formation contain more isotopically juvenile compositions. The increase in juvenile compositions also coincides with elevated total organic carbon (TOC) and phosphorous (P) content of these sediments, which are thought to reflect an increase in nutrient supply associated with the weathering of basaltic sources. Possible, relatively juvenile, basaltic sources include the Wankanki Supersuite in the western Musgraves and the Derim Derim-Galiwinku large igneous province (LIP). The transition into juvenile, basaltic sources directly before a supersequence-bounding unconformity, is here interpreted to reflect uplift and erosion of the Derim Derim-Galiwinku LIP, rather than an influx of southern, Musgrave sources. A new baddeleyite crystallization age of 1312.9 ± 0.7 Ma provides both a tight constraint on the age of this LIP, along with its associated magmatic uplift, as well as providing a minimum age constraint for Roper Group deposition. The supra-Roper Group lower and upper Jamison sandstones were both sourced from the Musgrave Province, at least 300 million years after deposition of the Kyalla Formation. An up-section increase in isotopically juvenile compositions seen in these rocks, are interpreted to document the continuous exhumation of the western Musgrave Province. The overlying Hayfield mudstone received detritus from both the Musgrave and Arunta regions, and its isotopic geochemistry reveals affinities with other early Neoproterozoic basins (e.g. Amadeus, Victoria and Officer basins), indicating the potential for inter-basin correlations.

  • <div>This data package contains interpretations of airborne electromagnetic (AEM) conductivity sections in the Exploring for the Future (EFTF) program’s Eastern Resources Corridor (ERC) study area, in south eastern Australia. Conductivity sections from 3 AEM surveys were interpreted to provide a continuous interpretation across the study area – the EFTF AusAEM ERC (Ley-Cooper, 2021), the Frome Embayment TEMPEST (Costelloe et al., 2012) and the MinEx CRC Mundi (Brodie, 2021) AEM surveys. Selected lines from the Frome Embayment TEMPEST and MinEx CRC Mundi surveys were chosen for interpretation to align with the 20&nbsp;km line-spaced EFTF AusAEM ERC survey (Figure 1).</div><div>The aim of this study was to interpret the AEM conductivity sections to develop a regional understanding of the near-surface stratigraphy and structural architecture. To ensure that the interpretations took into account the local geological features, the AEM conductivity sections were integrated and interpreted with other geological and geophysical datasets, such as boreholes, potential fields, surface and basement geology maps, and seismic interpretations. This approach provides a near-surface fundamental regional geological framework to support more detailed investigations. </div><div>This study interpreted between the ground surface and 500&nbsp;m depth along almost 30,000 line kilometres of nominally 20&nbsp;km line-spaced AEM conductivity sections, across an area of approximately 550,000&nbsp;km2. These interpretations delineate the geo-electrical features that correspond to major chronostratigraphic boundaries, and capture detailed stratigraphic information associated with these boundaries. These interpretations produced approximately 170,000 depth estimate points or approximately 9,100 3D line segments, each attributed with high-quality geometric, stratigraphic, and ancillary data. The depth estimate points are formatted for compliance with Geoscience Australia’s (GA) Estimates of Geological and Geophysical Surfaces (EGGS) database, the national repository for standardised depth estimate points. </div><div>Results from these interpretations provided support to stratigraphic drillhole targeting, as part of the Delamerian Margins NSW National Drilling Initiative campaign, a collaboration between GA’s EFTF program, the MinEx CRC National Drilling Initiative and the Geological Survey of New South Wales. The interpretations have applications in a wide range of disciplines, such as mineral, energy and groundwater resource exploration, environmental management, subsurface mapping, tectonic evolution studies, and cover thickness, prospectivity, and economic modelling. It is anticipated that these interpretations will benefit government, industry and academia with interest in the geology of the ERC region.</div>